Andrzej Katrusiak

Bio: Andrzej Katrusiak is an academic researcher from Adam Mickiewicz University in Poznań. The author has contributed to research in topics: Hydrogen bond & Molecule. The author has an hindex of 36, co-authored 512 publications receiving 7708 citations. Previous affiliations of Andrzej Katrusiak include Polish Academy of Sciences.

Ferroelectricity in NH ⋯ N Hydrogen Bonded Crystals

Abstract: $\mathrm{NH}\ensuremath{\cdots}\mathrm{N}$ hydrogen bonded crystals of $[{\mathrm{C}}_{6}{\mathrm{H}}_{7}{\mathrm{N}}_{2}{]}^{+}\ifmmode \dot{}\else \{}\fi{}{\mathrm{ClO}}_{4}^{\phantom{\rule{0ex}{0ex}}\ensuremath{-}}$ and $[{\mathrm{C}}_{6}{\mathrm{H}}_{7}{\mathrm{N}}_{2}{]}^{+}\ifmmode \dot{}\else \{}\fi{}{\mathrm{BF}}_{4}^{\phantom{\rule{0ex}{0ex}}\ensuremath{-}}$ undergo ferroelectric phase transitions at 3770(5) and 3781(5) K, respectively Owing to particularly simple structure, built of linear $\mathrm{NH}\ensuremath{\cdots}\mathrm{N}$ bonded aggregates, the spontaneous polarization of the crystals can be straightforwardly calculated from ionic displacements The $\mathrm{NH}\ensuremath{\cdots}\mathrm{N}$ bonded structures have been compared with transformations of analogous bistable $\mathrm{OH}\ensuremath{\cdots}\mathrm{O}$ hydrogen bonds in ${\mathrm{H}}_{2}\mathrm{O}$ ices and ${\mathrm{KH}}_{2}{\mathrm{PO}}_{4}$-type ferroelectrics

High-pressure crystallography

Abstract: Since the late 1950's, high-pressure structural studies have become increasingly frequent, following the inception of opposed-anvil cells, development of efficient diffractometric equipment (brighter radiation sources both in laboratories and in synchrotron facilities, highly efficient area detectors) and procedures (for crystal mounting, centring, pressure calibration, collecting and correcting data). Consequently, during the last decades, high-pressure crystallography has evolved into a powerful technique which can be routinely applied in laboratories and dedicated synchrotron and neutron facilities. The variation of pressure adds a new thermodynamic dimension to crystal-structure analyses, and extends the understanding of the solid state and materials in general. New areas of thermodynamic exploration of phase diagrams, polymorphism, transformations between different phases and cohesion forces, structure–property relations, and a deeper understanding of matter at the atomic scale in general are accessible with the high-pressure techniques in hand. A brief history, guidelines and requirements for performing high-pressure structural studies are outlined.

Ferroelectric order of parallel bistable hydrogen bonds.

Abstract: A new $\mathrm{N}\mathrm{H}\mathrm{\ensuremath{\cdots}}\mathrm{N}$ hydrogen-bonded ferroelectric crystal of $[{\mathrm{C}}_{\mathrm{6}}{\mathrm{H}}_{\mathrm{12}}{\mathrm{N}}_{\mathrm{2}}\mathrm{H}{\mathrm{]}}^{\mathrm{+}}\mathrm{R}\mathrm{e}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{\ensuremath{-}}}$ ($\mathrm{d}\mathrm{a}\mathrm{b}\mathrm{c}\mathrm{o}\mathrm{H}\mathrm{R}\mathrm{e}{\mathrm{O}}_{\mathrm{4}}$) exhibits exceptional dielectric properties that result from the unique structure where all the bistable $\mathrm{N}\mathrm{H}\mathrm{\ensuremath{\cdots}}\mathrm{N}$ hydrogen bonds are parallel and directed exactly in the same sense. Consequently, the main structural origin of the spontaneous polarization of the crystal is the identical orientation of the asymmetric $\mathrm{N}{\mathrm{H}}^{\mathrm{+}}\mathrm{\ensuremath{\cdots}}\mathrm{N}$ hydrogen bonds along [001]. This first observation of a ferroelectric with parallel arrangement of the $\mathrm{N}{\mathrm{H}}^{\mathrm{+}}\mathrm{\ensuremath{\cdots}}\mathrm{N}$ bonded aggregates, gives temperature-independent and the highest spontaneous polarization ever reported for an organic or water-soluble substance.

Mechanism of Pressure-Induced Phase Transitions, Amorphization, and Absorption-Edge Shift in Photovoltaic Methylammonium Lead Iodide.

Abstract: Our single-crystal X-ray diffraction study of methylammonium lead triiodide, MAPbI3, provides the first comprehensive structural information on the tetragonal phase II in the pressure range to 0.35 GPa, on the cubic phase IV stable between 0.35 and 2.5 GPa, and on the isostructural cubic phase V observed above 2.5 GPa, which undergoes a gradual amorphization. The optical absorption study confirms that up to 0.35 GPa, the absorption edge of MAPbI3 is red-shifted, allowing an extension of spectral absorption. The transitions to phases IV and V are associated with the abrupt blue shifts of the absorption edge. The strong increase of the energy gap in phase V result in a spectacular color change of the crystal from black to red around 3.5 GPa. The optical changes have been correlated with the pressure-induced strain of the MAPbI3 inorganic framework and its frustration, triggered by methylammonium cations trapped at random orientations in the squeezed voids.

Designing large triangular chiral macrocycles: efficient

Abstract: Triangular 30- and 27-membered hexaiminomacrocycles 4 and 5 of D3 and C3 symmetry, respectively, are readily obtained by unprecedented [3 + 3] cyclocondensation of (R,R)-1,2-diaminocyclohexane with, accordingly, terephthalaldehyde and isophthalaldehyde. The course of the reaction, leading to macrocyclization, is governed by conformational constraints imposed on the structural components of the intermediate products, as shown by molecular modeling. X-ray analysis of cocrystal 4·AcOEt revealed that the macrocycle symmetry significantly departs from ideal D3 symmetry due to crystal environment. Cyclic hexaamines 6 and 7 were prepared by sodium borohydride reduction of 4 and 5, respectively.

Organic–Inorganic Perovskites: Structural Versatility for Functional Materials Design

Abstract: Although known since the late 19th century, organic–inorganic perovskites have recently received extraordinary research community attention because of their unique physical properties, which make them promising candidates for application in photovoltaic (PV) and related optoelectronic devices. This review will explore beyond the current focus on three-dimensional (3-D) lead(II) halide perovskites, to highlight the great chemical flexibility and outstanding potential of the broader class of 3-D and lower dimensional organic-based perovskite family for electronic, optical, and energy-based applications as well as fundamental research. The concept of a multifunctional organic–inorganic hybrid, in which the organic and inorganic structural components provide intentional, unique, and hopefully synergistic features to the compound, represents an important contemporary target.

Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields

Abstract: : The unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio. Harmonic force fields are obtained using Density Functional Theory (DFT), MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set. DFT calculations use the Local Spin Density Approximation (LSDA), BLYP, and Becke3LYP (B3LYP) density functionals. Mid-IR spectra predicted using LSDA, BLYP, and B3LYP force fields are of significantly different quality, the B3LYP force field yielding spectra in clearly superior, and overall excellent, agreement with experiment. The MP2 force field yields spectra in slightly worse agreement with experiment than the B3LYP force field. The SCF force field yields spectra in poor agreement with experiment.The basis set dependence of B3LYP force fields is also explored: the 6-31G* and TZ2P basis sets give very similar results while the 3-21G basis set yields spectra in substantially worse agreements with experiment. jg

Crystal engineering: from molecule to crystal.

Abstract: How do molecules aggregate in solution, and how do these aggregates consolidate themselves in crystals? What is the relationship between the structure of a molecule and the structure of the crystal it forms? Why do some molecules adopt more than one crystal structure? Why do some crystal structures contain solvent? How does one design a crystal structure with a specified topology of molecules, or a specified coordination of molecules and/or ions, or with a specified property? What are the relationships between crystal structures and properties for molecular crystals? These are some of the questions that are being addressed today by the crystal engineering community, a group that draws from the larger communities of organic, inorganic, and physical chemists, crystallographers, and solid state scientists. This Perspective provides a brief historical introduction to crystal engineering itself and an assessment of the importance and utility of the supramolecular synthon, which is one of the most important concepts in the practical use and implementation of crystal design. It also provides a look to the future from the viewpoint of the author, and indicates some directions in which this field might be moving.